2,3-dimercapto-quinoxalines



United States Patent 3,223,706 2,3-DIMERCAPTO-QUINOXALINES Klaus Sasse, Cologne-.Stammheim, Richard Wegler, Leverkusen, and Giinter Unterstenhiifer, Opladen, Germany, assignors t0 Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a German corporation No Drawing. Filed Jan. 3, 1962, Ser. No. 164,190 Claims priority, application Germany, Jan. 26, 1961,

F 33,068 Claims. (Cl. 260-250) This invention relates to compounds of the structure N-Ri a N so Y R NRi wherein R is a member of the group consisting of hydrogen, halogen, nitro, trifluoromethyl, a lower alkyl radical up to 4 carbon atoms and a a lower alkoxy radical; R is a member of the group consisting of hydrogen, a hydroxy group, an alkyl, cycloalkyl, aryl, chloroaryl, aralkyl, alkylsulphonyl, arylsulphonyl radical and a primary and secondary amino group, and R is a member of the group consisting of-hydrogen, an alkyl, cycloalkyl, aralkyl, aryl, alkoxy, aryloxy, alkylmercapto, arylmercapto radical and a primary and secondary amino group.

More specifically this invention deals with compounds of the structure NRl wherein R is selected from the group consisting of an alkyl, chlorophenyl, arylamino and an arylsulfonyl radical and R is selected from the group consisting of the phenyl, alkoxy and a chlorophenylamino, dialkylamino and an arylmercapto radical. The compounds of the invention are prepared by reacting 2,3-dimercapto-quinoxalines of the structure with a compoundof the structure N-Rr Halogen-C R2 resulting in a compound of the structure N-R R 1 N S-C N so NRi

wherein R is a substituent which is inert to acid halides such as hydrogen, halogen, nitro, trifluoromethyl, a lower alkyl radical up to 4 carbon atoms and a lower alkoxy radical; R is a member of the group consisting of by- 3,223,706 Patented Dec. 14, 1965 drogen, a hydroxy group, an alkyl, cycloalkyl, aryl, chloroaryl, aralkyl, alkylsulfonyl, arylsulfonyl radical and a primary and secondary amino group and R is a member of the group consisting of hydrogen, an alkyl, cycloalkyl, aralkyl, aryl, hydrocyclic, alkoxy, aryloxy, alkylmercapto, arylmercapto radical and a primary and secondary amino group. i

As starting materials which may be used for the reaction according to the invention there may be mentioned for example: carboxylic acid-irnide halides, hydroxamic acid halides (hydroximic acid halides), carboxylic acidhydrazide halides or their derivatives with carbonyl compounds, carboxylic acid-N-sulphonyl-imide halides, imidocarbonic acid ester halides, imido-thiocarbonic acid ester halides, imido-carbonic acidamide halides, imidocarbonic acidhydrazide halides or their isomers.

More specifically, the process according to the invention i preferably carriedout in the presence of an acidbinding agent such as alkali metal or alkaline earth metal oxides, hydroxides, or carbonates, tertiary amines and the like. On the other hand, it is also possible to produce first the metal or ammonium salts of 2,3-dimercaptoquinoxaline or its derivatives substituted in the nucleus.

R l T \N/ SH with 2 mols of carbodiimide of the structure resulting in a compound of the structure wherein R is a member of the group consisting of hydro- N Rl gen, halogen, nitro-trifluoromethyl, a lower alkyl radicalup to 4 carbon atoms and a lower alkoxy radical; R and R are members of the group consisting of an alkyl, cycloalkyl, aryl, chloroaryl and an aralkyl.

The reactions proceed at a high speed even in the absence of any additives and at low temperatures, if the process is carried out in a suitable solvent for the barely soluble 2,3-dimercapto-quinoxaline. Dimethyl formamide is especially suitable.

The compounds of this invention are useful in the field of pest control agents and show, in particular, an outstanding acaricidal activity.

The new 2,3-dimercapto-quinoxalines being used as pest control agents, are chiefly for plant protection. They may be employed in compositions including diluents, extenders, fillers and conditioners.

' Example 1 19.4 g. of 2,S-dimercapto-quinoxaline are dissolved in a solution of 8 g. of sodium hydroxide in 75 ml. of water, the reaction mixture is treated first with 200 ml. of acetone, subsequently dropwise below C. (cooling with a mixture of ice and sodium chloride) with 28 g. of N- methyl-benzimide chloride. In order to complete the reaction, the mixture is afterstirred below 0 C. for /2 hour and then with ice-cooling for a further hour, subsequently treated with water and the precipitated solid product filtered off with suction. After drying of the precipitate, there are obtained, 28 g. of a compound of the formula N-CHa 14.5 g. of 2,3-dimercapto-quinoxaline are dissolved in a solution of 6 g. of sodium hydroxide in 70 ml. of water. The mixture is diluted with 200 ml. of acetone, 30 g. of pchlorophenyl-imidocarbonic acid-methyl ester chloride are then added dropwise below 15 C. With stirring and slight external cooling, the reaction mixture is afterstirred at room temperature for one hour, treated with Water, the precipitate formed is filtered off with suction and dried. In this way, 24 g. of a product of the formula are obtained. After re-crystallisation from glycol-monomethyl ether, the compound shows a decomposition point of about 200 C.

Example 3 formula is obtained in practically quantitative yield which, after re-crystallisation from butanol, melts at 166167 C.

Example 4 9.7 g. of 2,3-dimercapto-quinoxaline are dissolved in a solution of 4 g. sodium hydroxide in 50 ml. of water. This mixture is diluted with m1. of acetone and subsequently dropwise treated in a temperature range between -5 and 0 C. with 17.7 g. of pyruvic acid of the phenylhydrazide chloride of the formula In order to complete the reaction the mixture is stirred for an hour. After diluting with water the 2,3-dimercaptoquinoxaline compound is filtered out and recrystallized in a dioxane/methanol mixture to give 16 g. of a compound of the formula N-NH- COOHa M.P. C.

Example 5 The procedure of Example 4 was followed, but reacting 9.7 g. of 2,3-dimercapto-quinoxaline with 26.4 g. of N(p-tolylsulfonyl)-benzimide chloride of the formula melting point 78-80 C.

Example 6 According to the procedure of Example 4 there are obtained from 9.7 g. of 2,3-dimercapto-quinoxaline and 18.3 g. of phenylimino carbonic acid dimethylamidechloride of the formula g. of a compound of the formula a compound which solidifies glass-like without crystallizing. Example 7 In the procedure according to Example 4, 9.7 g. of

2,3-dimercapto-quinoxaline and 41.4 g. of p-chlorophenylimino-thiocarbonic acid ester chloride of pentachlorophenyl of the formula there are obtained 25 g. of a compound of the formula melting point 182 C., recrystallized from carbontetrachloride/ligroin.

In the same manner the compound of the following formula is obtained (from p-chloropheny-limide-carbonicacid-diethylamidechloride) and from the nitro, chloro and trifluoromethyl compound of the 2,3-dimercapto-quinoxaline there are obtained the following compounds of the formulae Example 8 According to the procedure of Example 4 there are obtained from 9.7 g. of 2,3-dimercapto-quinoxaline and 21.2 g. of phenylhydraZide-chloride of benzoic acid 18 g. of a compound of the formula What is claimed is: 1. A compound of the formula 2. A compound of the formula wherein R is a member selected from the group consisting of hydrogen, chloro, nitro, trifluoromethyl, lower alkyl containing up to 4 carbon atoms, and lower alkoxy; R is a member selected from the group consisting of a hydrogen, lower alkyl, phenyl, and ohlorophenyl; and R is a member selected from the group consisting of hydrogen. lower alkyl, phenyl, and chlorophenyl.

7 '8 3. A compound of the formula 5. A compound of the formula NCHa NOH3 N s-o N CH3 [1 j g 5 CH3O Y Q N \SC/ \N sO N-GH: 4. A compound of the formula 10 3 NCH; References Cited by the Examiner N SC\ UNITED STATES PATENTS 01- 15 3,040,046 6/1962 Sasse et a1 260--250 \N/\ NICHOLAS s. RIZZO, Primary Examiner.

IRVING MARCUS, WALTER A. MODANCE,

\ \N-CH3 20 Examimer. 

2. A COMPOUND OF THE FORMULA 